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/*
* Copyright (c) 2019 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef MODULES_AUDIO_CODING_NETEQ_HISTOGRAM_H_
#define MODULES_AUDIO_CODING_NETEQ_HISTOGRAM_H_
#include <string.h> // Provide access to size_t.
#include <vector>
#include "absl/types/optional.h"
namespace webrtc {
class Histogram {
public:
// Creates histogram with capacity |num_buckets| and |forget_factor| in Q15.
Histogram(size_t num_buckets,
int forget_factor,
absl::optional<double> start_forget_weight = absl::nullopt);
virtual ~Histogram();
// Resets the histogram to the default start distribution.
virtual void Reset();
// Add entry in bucket |index|.
virtual void Add(int index);
// Calculates the quantile at |probability| (in Q30) of the histogram
// distribution.
virtual int Quantile(int probability);
// Apply compression or stretching to the histogram.
virtual void Scale(int old_bucket_width, int new_bucket_width);
// Returns the number of buckets in the histogram.
virtual int NumBuckets() const;
// Returns the probability for each bucket in Q30.
std::vector<int> buckets() const { return buckets_; }
// Made public for testing.
static std::vector<int> ScaleBuckets(const std::vector<int>& buckets,
int old_bucket_width,
int new_bucket_width);
// Accessors only intended for testing purposes.
int base_forget_factor_for_testing() const { return base_forget_factor_; }
int forget_factor_for_testing() const { return forget_factor_; }
absl::optional<double> start_forget_weight_for_testing() const {
return start_forget_weight_;
}
private:
std::vector<int> buckets_;
int forget_factor_; // Q15
const int base_forget_factor_;
int add_count_;
const absl::optional<double> start_forget_weight_;
};
} // namespace webrtc
#endif // MODULES_AUDIO_CODING_NETEQ_HISTOGRAM_H_